1. Field of the Invention
The present invention relates to a wafer support device and a wafer support method and more particularly, to a wafer support device and a wafer support method with high-accuracy positioning and pressure control in an apparatus for performing an electrical characteristic test of a chip or the like on a semiconductor wafer.
2. Description of Related Arts
In general, an apparatus for an electrical characteristic test, performs the test by bringing a probe in contact with the electrode of each chip on a wafer, refereed to as a prober. As Japanese Published Application H9-22927A disclosed, the positioning of the probe and the prober is used a base for moving the wafer in the X, Y, Z, or θ direction and performed by image processing or the like to bring the probe in contact with each chip. In the case of the mechanism, for the Z direction in association with the contact pressure of the probe, after setting at the time of the initial calibration, control is performed by only the position in the Z direction not depending upon the contact pressure.
Recently, according to the reduction in pitch of a semiconductor chip to be targeted for test proceeds, a size and a thickness of a probe for use in the test also has been reduced. However, the contact load for establishing an electrical connection is also required to some degrees, therefore, it is not possible to ascertain the contact state of the probe with precision only with positioning by the positional control as in the prior art. Under such circumstances, Japanese published application 2002-100666A discloses a lifting device for a stage which comprises a correction table corresponding to the magnitude of the load applied on the stage and the positional deviation amounts in the X axis direction and the Y axis direction of the stage. Further, Japanese Patent 3267938B discloses a prober for reducing the moment generating when a probe brought in contact with a wafer applies the stage with pressure, by using a plurality of actuators on a plurality of sites of a stage.
However, with the increase in diameter of a wafer, and a further reduction in pitch, the positioning is required to be more precise.